Frequent Serotypes Research Articles

Sentinel surveillance in bacterial pneumonia in children under 5 years old in a fourth-level pediatric hospital in Colombia 2016-2022

ObjectivesSentinel surveillance for bacterial pneumonia (SSBP) allows the monitoring of immunopreventable diseases. The results of the SSBP carried out at HOMI, Fundación Hospital pediátrico de la Misericordia, are presented. MethodsThe daily active search for cases was carried out in accordance with the protocol of the Pan American Health Organization from January 2016 to December 2022. ResultsThere were 6970 suspected cases of bacterial pneumonia (BP). Among the 3048 (43.7%) patients with probable BP, cultures were obtained from 2777 (91.1%), and BP was confirmed in 190 (6.2%). The causes were Streptococcus pneumoniae in 98 (51.6%) cases, Spn19A in 47 (48%), Spn3 in 16 (16%), and Spn6C in 4 (4%). Haemophilus influenzae was found in 32 (16.8%) cases: non-typeable H. influenzae in 20 (62.5%), H. influenzae type b in five (15.6%), and H. influenzae type a in two (6.2%). Other bacteria were found in 60 (31.6%) cases. A total of 51.6% and 42.9% of patients with S. pneumoniae had decreased sensitivity to penicillin and ceftriaxone, respectively. ConclusionsThe serotypes included in the conjugate vaccines for pneumococcus and H. influenzae b decreased significantly, and serotype turnover was observed. Among the S. pneumoniae cases, Spn19A, Spn3, and Spn6C were the most frequent serotypes and associated with multiresistance. The SSBP allows us to determine the clinical behavior of the disease and to detect the serotypes emergence.

Invasive Pneumococcal Infections Among Moroccan Children: Pneumococcal Vaccination Challenges in the Mature Vaccine Era.

Streptococcus pneumoniae, a major contributor to global morbidity and mortality, disproportionately affects children, the elderly, and immunocompromised individuals. Despite vaccination efforts, the challenge of serotype replacement highlights the ongoing struggle against invasive pneumococcal diseases (IPD) in Morocco, emphasizing the need for updated public health strategies and vaccine efficacy assessments. This study was conducted at the Ibn Rochd University Hospital Center and the Mohammed VI University Hospital Center from 2019 to 2022, focusing on hospitalized children. It involved the analysis of 74 strains of IPD, assessing the distribution of pneumococcal serotypes and their antibiotic sensitivity in the post-vaccination era. The prevalence of meningitis or meningo-encephalitis was found to be 66% among the study subjects, with the most frequent serotypes being 3, 19A, 6B, 14, and 11. These serotypes varied significantly by age and location. Coverage rates for the pneumococcal conjugate vaccines, PCV-10 and PCV-13, were 20.27% and 56.75%, respectively. Notably, 43% of the strains were non-vaccine serotypes, with serotypes 3 and 19 accounting for 36% of the infections in children, indicating a lack of vaccine efficacy against these types. Additionally, 31.3% of the strains were Penicillin non-susceptible Streptococcus pneumoniae (PNSP), with 81.25% associated with non-vaccine serotypes. This study highlights the persistence of IPD in Moroccan children, revealing significant challenges despite vaccination efforts. With the reintroduction of PCV-13, concerns about the efficacy against non-vaccine serotypes, particularly 3 and 19A, remain. Continuous surveillance and adaptable vaccination strategies are essential to combat these serotype replacements and ensure the effectiveness of future preventive measures.

Occurrence, serotypes and virulence characteristics of Shiga toxin-producing and Enteropathogenic Escherichia coli isolates from dairy cattle in South Africa

Shiga toxin-producing and Enteropathogenic Escherichiacoli are foodborne pathogens commonly associated with diarrheal disease in humans. This study investigated the presence of STEC and EPEC in 771 dairy cattle fecal samples which were collected from 5 abattoirs and 9 dairy farms in South Africa. STEC and EPEC were detected, isolated and identified using culture and PCR. Furthermore, 339 STEC and 136 EPEC isolates were characterized by serotype and major virulence genes including stx1, stx2, eaeA and hlyA and the presence of eaeA and bfpA in EPEC. PCR screening of bacterial sweeps which were grown from fecal samples revealed that 42.2% and 23.3% were STEC and EPEC positive, respectively. PCR serotyping of 339 STEC and 136 EPEC isolates revealed 53 different STEC and 19 EPEC serotypes, respectively. The three most frequent STEC serotypes were O82:H8, OgX18:H2, and O157:H7. Only 10% of the isolates were classified as “Top 7” STEC serotypes: O26:H2, 0.3%; O26:H11, 3.2%; O103:H8, 0.6%; and O157:H7, 5.9%. The three most frequent EPEC serotypes were O10:H2, OgN9:H28, and O26:H11. The distribution of major virulence genes among the 339 STEC isolates was as follows: stx1, 72.9%; stx2, 85.7%; eaeA, 13.6% and hlyA, 69.9%. All the 136 EPEC isolates were eaeA-positive but bfpA-negative, while 46.5% carried hlyA. This study revealed that dairy cattle are a major reservoir of STEC and EPEC in South Africa. Further comparative studies of cattle and human STEC and EPEC isolates will be needed to determine the role played by dairy cattle STEC and EPEC in the occurrence of foodborne disease in humans.Please kindly check and confirm the country and city name in affiliation [6].This affiliation is correct.Please kindly check and confirm the affiliationsConfirmed. All Affiliations are accurate

Anticipated Effects of Higher-valency Pneumococcal Conjugate Vaccines on Colonization and Acute Otitis Media.

Bacterial etiologies of acute otitis media (AOM) have shifted from the introduction of pneumococcal conjugate vaccines (PCVs), antibiotic selection and competition among species. We characterized Streptococcus pneumoniae ( Spn ), Haemophilus influenzae ( Hflu ) and Moraxella catarrhalis ( Mcat ) in the nasopharynx during well-child healthy visits and at the onset of AOM, and in middle ear fluid (MEF) of children with AOM to assess anticipated effects of higher-valency PCVs (PCV15 and PCV20). From September 2021 to September 2023, we conducted a prospective longitudinal cohort study of PCV13 immunized children 6-36 months old. MEF was collected via tympanocentesis. Serotyping and antibiotic susceptibility testing were performed on Spn , Hflu and Mcat isolates. We obtained 825 nasopharyngeal and 216 MEF samples from 301 children. The order of frequency of nasopharyngeal colonization was Mcat , Spn and Hflu ; Hflu was the predominant otopathogen in MEF. Among Spn isolates, non-PCV15, non-PCV20 serotypes predominated in the nasopharynx and in MEF; the most frequent serotype was 35B. Among MEF samples, 30% of Spn isolates were amoxicillin nonsusceptible; 23% of Hflu isolates and 100% of Mcat isolates were β-lactamase-producing. The majority of Spn isolates among young children were non-PCV15, non-PCV20 serotypes, especially serotype 35B; therefore, the impact of higher-valency PCVs in reducing pneumococcal colonization or AOM is expected to be limited. Hflu continues to be the most frequent AOM pathogen. Antibiotic susceptibility data suggest a high dose of amoxicillin/clavulanate or alternative drugs that are effective against contemporary mix of otopathogens could be considered for optimal empiric selection to provide the best efficacy.

Nasopharyngeal Carriage of Streptococcus pneumoniae in Tunisian Healthy under-Five Children during a Three-Year Survey Period (2020 to 2022).

We aimed to assess the prevalence of nasopharyngeal pneumococcal carriage and to determine serotype distribution, antibiotic susceptibility patterns, and evolutionary dynamics of Streptococcus pneumoniae isolates in healthy under-five children. Nasopharyngeal swabs were collected from healthy children over three survey periods between 2020 and 2022. All pneumococcal isolates were serotyped and tested for antimicrobial susceptibility. A total of 309 S. pneumoniae isolates were collected, with an overall prevalence of nasopharyngeal pneumococcal carriage of 24.4% (CI95%: [22-26.8%]). These isolates were classified into 25 different serotypes. The most common serotypes were 14 (14.9%), 19F (12%), 6B (10.4%), and 23F (7.4%), which are covered by the PCV10 vaccine, as well as 19A (8.4%) and 6A (7.8%), which are covered by the PCV13 vaccine. A significant decrease in the proportion of serotype 19F (p = 0.001) and an increase in serotypes 19A (p = 0.034) and 6A (p = 0.029) were observed between the three survey periods. Multidrug resistance (MDR) was noted for 56.6% of the isolates. A significant association with antimicrobial resistance was observed for the most frequent serotypes, mainly serotype 19A. In conclusion, one-quarter of healthy under-five children in Tunisia carried S. pneumoniae in their nasopharynx. A dominance of vaccine serotypes significantly associated with antimicrobial resistance was recorded.

Outpatient Visits and Antibiotic Use Due to Higher-Valency Pneumococcal Vaccine Serotypes.

In 2022-2023, 15- and 20-valent pneumococcal conjugate vaccines (PCV15/PCV20) were recommended for infants. We aimed to estimate the incidence of outpatient visits and antibiotic prescriptions in US children (≤17 years) from 2016-2019 for acute otitis media, pneumonia, and sinusitis associated with PCV15- and PCV20-additional (non-PCV13) serotypes to quantify PCV15/20 potential impacts. We estimated the incidence of PCV15/20-additional serotype-attributable visits and antibiotic prescriptions as the product of all-cause incidence rates, derived from national health care surveys and MarketScan databases, and PCV15/20-additional serotype-attributable fractions. We estimated serotype-specific attributable fractions using modified vaccine-probe approaches incorporating incidence changes post-PCV13 and ratios of PCV13 versus PCV15/20 serotype frequencies, estimated through meta-analyses. Per 1000 children annually, PCV15-additional serotypes accounted for an estimated 2.7 (95% confidence interval, 1.8-3.9) visits and 2.4 (95% CI, 1.6-3.4) antibiotic prescriptions. PCV20-additional serotypes resulted in 15.0 (95% CI, 11.2-20.4) visits and 13.2 (95% CI, 9.9-18.0) antibiotic prescriptions annually per 1000 children. PCV15/20-additional serotypes account for 0.4% (95% CI, 0.2%-0.6%) and 2.1% (95% CI, 1.5%-3.0%) of pediatric outpatient antibiotic use. Compared with PCV15-additional serotypes, PCV20-additional serotypes account for > 5 times the burden of visits and antibiotic prescriptions. Higher-valency PCVs, especially PCV20, may contribute to preventing pediatric pneumococcal respiratory infections and antibiotic use.

Serotype distribution, clinical characteristics, and antimicrobial resistance of pediatric invasive pneumococcal disease in Colombia during PCV10 mass vaccination (2017-2022).

Invasive Pneumococcal Disease (IPD) causes significant morbidity and mortality in children under 5 y. Colombia introduced PCV10 vaccination in 2012, and the Neumocolombia network has been monitoring IPD in pediatric patients since 2008. This study is a secondary analysis of a prospective cohort involving pediatric patients with IPD admitted to 17 hospitals in Colombia, from January 1st, 2017, to December 31st, 2022. We present data on serotypes (Spn), clinical characteristics, and resistance patterns. We report 530 patients, 215 (40.5%) were younger than 24 months. Among these, 344 cases (64.7%) presented with pneumonia, 95 (17.9%) with primary bacteremia, 53 (10%) with meningitis, 6 (1.1%) had pneumonia and meningitis, and 32 (6%) had other IPD diagnosis. The median hospital stay was 12 days (RIQ 8-14 days), and 268 (50.6%) were admitted to the ICU, of whom 60 (11.3%) died. Serotyping was performed in 298 (56.1%). The most frequent serotypes were Spn19A (51.3%), Spn6C (7.7%), Spn3 (6.7%), Spn6A (3.6%), and Spn14 (3.6%). Of 495 (93%) isolates with known susceptibility, 46 (9.2%) were meningeal (M) and 449 (90.7%) non-meningeal (NM). Among M isolates, 41.3% showed resistance to penicillin, and 21.7% decreased susceptibility to ceftriaxone. For NM isolates, 28.2% had decreased susceptibility to penicilin, and 24.2% decreased susceptibility to ceftriaxone. Spn19A showed the highest resistant to penicillin at 47% and was linked to multiresistance. The prevalence of PCV10-included serotypes decreased, while serotypes 19A and 6C increased, with Spn19A being associated with multiresistance. These findings had played a crucial role in the decision made by Colombia to modify its immunization schedule by switching to PCV13 in July 2022.

Adult non-invasive pneumococcal pneumonia in Portugal is dominated by serotype 3 and non-PCV13 serotypes 3-years after near universal PCV13 use in children.

Non-invasive pneumococcal pneumonia (NIPP) is possibly the most frequent infection by Streptococcus pneumoniae in adults. However, the herd effect of vaccinating children in adult NIPP (aNIPP) remains poorly characterized. We determined the serotype distribution and antimicrobial susceptibility of isolates causing aNIPP (>18 years) in 2016-2018 in Portugal; 3 years with near universal vaccination of children with the 13-valent conjugate vaccine (PCV13), following over a decade of significant PCV use in children in the private market. Among the 1,149 aNIPP isolates, the most frequent serotypes detected were: 3 (n = 168, 14.6%), 11A (n = 102, 8.9%), 19F (n = 70, 6.1%), 23A and 23B (n = 62, 5.4% each), 9N (n = 60, 5.2%), 8 and 29/35B (n = 43, 3.7% each); together accounting for 53% of all isolates. The serotype distribution causing aNIPP was stable in 2016-2018, with the serotypes included in PCV7 still being important causes of disease and serotype 3, a PCV13 serotype, remaining the leading cause of aNIPP. There was an increase in penicillin non-susceptibility from 17% in 2016 to 24% in 2018 (p = 0.018). Some PCV13 serotypes, such as 14, 19A and 19F were associated to resistance, which may have contributed to their persistence. The fact that close to 20% of aNIPP is caused by four non-vaccine serotypes (23A, 23B, 9N, and 29/35B) and that there were significant differences in serotype distribution relative to invasive disease, stress the importance of maintaining the surveillance of these infections. The lack of a continued herd effect from vaccinating children and the significant fraction of aNIPP potentially preventable by PCV13 (30%), PCV15 (34%), PCV20 (53%) and the 23-valent polysaccharide vaccine (61%) underscore the importance of considering the broader use of pneumococcal vaccines in adults.

Genetic diversity and biofilm formation ofinvasive and noninvasive Streptococcus agalactiae isolates: Emergence of hypervirulentCC19 strains in Tehran, Iran.

The prevalence of Streptococcus agalactiae infections in adult populations is increasing. The current study aimed to characterize the genetic features of S. agalactiae strains responsible for different infections. Across-sectional study was performed on 65 S. agalactiae strains (30 invasive and 35 noninvasive) isolated from non-pregnant women. All S. agalactiae isolates were confirmed by atr and dltS PCR assays. Antibiotic susceptibility patterns were determined using the disk diffusion method. Biofilm production was investigated by microtiter plate assay. PCR was done to detect resistance determinants. Isolates were characterized using the multilocus sequence typing (MLST) method. cMLSB, iMLSB, and M phenotypes accounted for 47.7%, 30.8%, and 6.2%, respectively. MDR was detected in 15.4% of noninvasive and 44.6% of invasive isolates. MtP assay indicated that 80% of isolates were biofilm producers. Biofilm formation was common among noninvasive compared with invasive strains (94.3% versus 66.7%). tet (M) (46.2%) and erm (B) (69.2%) were the most prevalent tetracycline and macrolide-resistance genes. The most prevalent serotype was type III (50.8%), followed by Ia (18.4%), II (15.4%), V (12.3%), and IV (3.1%). The frequency of serotype III among biofilm producer strains (81.8%) was found to be significantly higher than that of non-producer isolates (18.2%) (P < 0.05). S. agalactiae was resolved within four clonal complexes, including CC19 (46.2%; in both invasive and noninvasive), followed by CC23 (30.8%; only noninvasive isolates), CC1 (15.4%; only noninvasive isolates) and CC17 (7.6%; only invasive isolates). Themain sequence types (STs) found were ST19 (27.7%), ST17 (7.7%), ST27 (6.2%), and ST28 (4.6%) linked with invasive infections and ST23 (18.4%), ST933 (12.3%), ST644 (9.2%), ST19 (7.7%), ST1 (6.2%) found in noninvasive infections. The high prevalence of CC19 and CC23 clones among S. agalactiae strains reflects the emergence of these lineages as successful clones in Iran.

1735. Impact of Children Universal Pneumococcal Vaccination (PCV7v/PCV13v) on Pneumococcal Invasive Disease Hospitalizations in a Private General Hospital, Uruguay

Abstract Background In 2008 Uruguay included pneumococcal conjugate vaccine (PCV) 7valent in children´s vaccination program (2+1). In 2010 PCV13 replaced PCV7. Since 2015, adults at risk of invasive pneumococcal disease (IPD) may receive 23 valent polysaccharide vaccine (PV23) or combined schedule PCV13+PV23. Objective: to assess the impact of this strategy on IPD hospitalization. Methods Rates per 10,000 discharges (Confidence Interval 95 %), diseases and serotypes (ST) are described before PCV7 vaccination (2006-2007), the year of vaccine implementation (2008), early after implementation (2009-2015) and late after implementation (2016-2022), the last 3 years during COVID-19 pandemic. Results In 2006-2022 were 33 IPD cases in children and 88 in adults over 15 years old. Children´s hospitalization median annual rates were as follow 2006-2007: 50 (25-75); 2008: 18,5 (-2-39); 2009-2015: 8,5 (3-14); 2016-2022: 4 (0-8); percentages of rate reduction were 82,5% and 92% (p&amp;lt; 0.0000). In adults 2006-2007: 17 (10-25); 2008: 13,4 (4,62-22,1); 2009-2015: 6,6 (4,4-9); 2016-2022: 6 (3,5-8,5); percentages of rate reduction were 63,5% and 66 % (p= 0,0001). Pneumococcal pneumonia (PP) was the most frequent disease in children 22/33 (66,6%), followed by bacteremia 8/32. PP was also in adults 68/88 (77.2,7%), followed by meningitis (7/88). One non vaccinated child died in 2008. Case fatality rate in adults was 9% (8/88), 3 died in 2006-2007, 2 in 2009-20215 and 3 in 2016-2022. 24 different ST were isolated in adults. Most frequent ST were 12F(15), 7F(11), 1(8), 8(7), 3(6) and 5(6). PCV13 would cover 38/88 (43%). A significant decline in PCV13 serotypes (PCV13-ST) was observed comparing the period prior PCV 17/22 (77%) with the late period 8/24 (34%) (p&amp;lt; 0.0000). 15 different ST were isolated in children: 26 PCV13-ST. 16 prior 2008: most frequent ST 1(5), 14(4), 3(2) and 5(2). In 2009-2022 13 hospitalizations; PCV13-ST: 1(2), 19A(2), 14(1), 6B&amp;lt; (1), 9V(1), 3(1) and non PCV13-ST: 7B/C(1), 24F(1), 13(1), 15A(1), 15B(1). A significant decline of PCV13-ST was observed comparing the period prior PCV (15/16, 94%) with the late period (2/4, 50 %) (p&amp;lt; 0.0000). Conclusion There was a reduction in children’s discharge rates and in adults´ probably due to herd effect. Adult vaccination will improve individual immunization. Disclosures María Catalina Pírez, Pediatrician, Pediatric infectologist, microbiologist Professor of pediatric, Degree V, Merck, Pfizer: Expert Testimony|Merck, Pfizer: Honoraria

Epidemiology of Pneumococcal Pneumonia in Louisville, Kentucky, and Its Estimated Burden of Disease in the United States.

Streptococcus pneumoniae remains a primary pathogen in hospitalized patients with community-acquired pneumonia (CAP). The objective of this study was to define the epidemiology of pneumococcal pneumonia in Louisville, Kentucky, and to estimate the burden of pneumococcal pneumonia in the United States (US). This study was nested in a prospective population-based cohort study of all adult residents in Louisville, Kentucky, who were hospitalized with CAP from 1 June 2014 to 31 May 2016. In hospitalized patients with CAP, urinary antigen detection of 24 S. pneumoniae serotypes (UAD-24) was performed. The annual population-based pneumococcal pneumonia incidence was calculated. The distribution of S. pneumoniae serotypes was characterized. Ecological associations between pneumococcal pneumonia and income level, race, and age were defined. Mortality was evaluated during hospitalization and at 30 days, 6 months, and 1 year after hospitalization. Among the 5402 CAP patients with a UAD-24 test performed, 708 (13%) patients had pneumococcal pneumonia. The annual cumulative incidence was 93 pneumococcal pneumonia hospitalizations per 100,000 adults (95% CI = 91-95), corresponding to an estimated 226,696 annual pneumococcal pneumonia hospitalizations in the US. The most frequent serotypes were 19A (12%), 3 (11%), and 22F (11%). Clusters of cases were found in areas with low incomes and a higher proportion of Black or African American population. Pneumococcal pneumonia mortality was 3.7% during hospitalization, 8.2% at 30 days, 17.6% at 6 months, and 25.4% at 1 year after hospitalization. The burden of pneumococcal pneumonia in the US remains significant, with an estimate of more than 225,000 adults hospitalized annually, and approximately 1 out of 4 hospitalized adult patients dies within 1 year after hospitalization.

Evolution of the serotypes causing invasive pneumococcal disease along 2008-2022 in a Level 2 Public Hospital of the Madrid Region, in relation to their inclusion in different conjugate vaccines

The use of conjugate vaccines against Streptococcus pneumoniae originates changes in the invasive pneumococcal disease (IPD). The aim of this study was to in vestigate the evolution of S. pneumoniae serotypes isolated in the Hospital Universitario de Getafe between 2008 and 2022. 313 of S. pneumoniae strains were studied. Serotyping was carried out by latex agglutination (Pneumotest-latex) and the Quellung reaction. In addition, the minimal inhibitory concentration (MIC) was determined against penicillin, erythromycin and levofloxacin by the concentration gradient method (E-test) according the EUCAST breakpoints. The most frequent serotypes throughout the study period were 8, 3, 19A, 1, 11A and 22F corresponding to 46.6% of the isolates. Along 2008-2012 the serotypes 3, 1, 19A, 7F, 6C and 11A represented altogether 53.6% of the isolates. Between 2013 and 2017 the serotypes 3, 8, 12F, 19A, 22F and 19F grouped 51% of the isolates. During 2018-2022 the serotypes 8, 3, 11A, 15A, 4 and 6C included the 55.5% of the cases. In total 5 strains (1.6%) were penicillin resistant, 64 (20.4%) erythromycin resistant and 11 (3.5%) levofloxacin resistant. The MIC50 and MIC90 levels maintained stables along the time. The conjugate vaccines use with different serotype coverage conditioned a decrease of the vaccine-included and an increase of non-covered. Despite these changes, the global antimicrobial susceptibility patterns to erythromycin and levofloxacin maintained relatively stables. The resistance a penicillin was low, not finding this type of resistant strains in the last study period.

Genomic classification and antimicrobial resistance profiling of Streptococcus pneumoniae and Haemophilus influenzae isolates associated with paediatric otitis media and upper respiratory infection

Acute otitis media (AOM) is the most common childhood bacterial infectious disease requiring antimicrobial therapy. Most cases of AOM are caused by translocation of Streptococcus pneumoniae or Haemophilus influenzae from the nasopharynx to the middle ear during an upper respiratory tract infection (URI). Ongoing genomic surveillance of these pathogens is important for vaccine design and tracking of emerging variants, as well as for monitoring patterns of antibiotic resistance to inform treatment strategies and stewardship.In this work, we examined the ability of a genomics-based workflow to determine microbiological and clinically relevant information from cultured bacterial isolates obtained from patients with AOM or an URI. We performed whole genome sequencing (WGS) and analysis of 148 bacterial isolates cultured from the nasopharynx (N = 124, 94 AOM and 30 URI) and ear (N = 24, all AOM) of 101 children aged 6–35 months presenting with AOM or an URI. We then performed WGS-based sequence typing and antimicrobial resistance profiling of each strain and compared results to those obtained from traditional microbiological phenotyping.WGS of clinical isolates resulted in 71 S. pneumoniae genomes and 76 H. influenzae genomes. Multilocus sequencing typing (MSLT) identified 33 sequence types for S. pneumoniae and 19 predicted serotypes including the most frequent serotypes 35B and 3. Genome analysis predicted 30% of S. pneumoniae isolates to have complete or intermediate penicillin resistance. AMR predictions for S. pneumoniae isolates had strong agreement with clinical susceptibility testing results for beta-lactam and non beta-lactam antibiotics, with a mean sensitivity of 93% (86–100%) and a mean specificity of 98% (94–100%). MLST identified 29 H. influenzae sequence types. Genome analysis identified beta-lactamase genes in 30% of H. influenzae strains, which was 100% in agreement with clinical beta-lactamase testing. We also identified a divergent highly antibiotic-resistant strain of S. pneumoniae, and found its closest sequenced strains, also isolated from nasopharyngeal samples from over 15 years ago.Ultimately, our work provides the groundwork for clinical WGS-based workflows to aid in detection and analysis of H. influenzae and S. pneumoniae isolates.

Trends in antimicrobial resistance of Shigella species in Peru, 2011-2020.

To describe the frequency of antimicrobial resistance rates and spatial-temporal distribution of Shigella species from the last 10 years in Peru. A cross-sectional descriptive study was carried out. A total of 1668 Shigella strains, remitted as part of the national enteric pathogen surveillance from 2011 to 2020, were analysed. The strains were confirmed by conventional tests and serotyped with polyvalent and monovalent antibodies. Also, antimicrobial susceptibility was performed according to the Kirby-Bauer method. The most frequent Shigella species was S. sonnei (49.2%), followed by S. flexneri (42.2%), S. boydii (7.9%) and S. dysenteriae (0.7%). Phase II (46.29%) was the most frequent serotype in S. sonnei, serotype 2a (43.61%) in S. flexneri, serotype 2 in S. boydii and serotype 4 in S. dysenteriae. High rates of resistance were detected for trimethoprim/sulfamethoxazole (91.0%), tetracycline (88.4%), ampicillin (73.9%) and chloramphenicol (64.9%), moderate rates for amoxicillin/clavulanic acid (25.1%), ciprofloxacin (16.7%) and nalidixic acid (14.8%), and low rates for cefotaxime (1.74%), nitrofurantoin (0.7%) and ceftazidime (0.6%). Moreover, antimicrobial resistance to fluoroquinolones increased considerably from 2017 to 2020. S. sonnei was the most frequent species, which have a large proportion of strains resistant to trimethoprim/sulfamethoxazole, and a growing trend of resistance to ciprofloxacin and nalidixic acid. This increase in resistance to commonly used antibiotics in treatments is alarming, threatening the control and management of these currently treatable infections.

Epidemiology of Streptococcus pneumoniae Serotypes in Jordan Amongst Children Younger than the Age of 5: A National Cross-Sectional Study.

Streptococcus pneumoniae infections are a major cause of mortality and morbidity worldwide. In Jordan, pneumococcal conjugate vaccines (PCVs) are not included in the national vaccination program. Due to the current availability of several PCVs, including PCV-10, PCV-13, and PCV-15, along with PCV-20, currently undergoing pediatric approvals globally, the decision to introduce PCVs and their selection should be based on valid local data on the common serotypes of Streptococcus pneumoniae. This cross-sectional study aimed to identify the frequency of serotypes of Streptococcus pneumoniae in children aged below 5 years hospitalized with invasive pneumococcal diseases (IPDs), including pneumonia, septicemia, and meningitis, during the study's duration in representative areas of Jordan. Serotyping for culture-positive cases was based on the capsular reaction test, known as the Quellung reaction. qPCR was conducted on the blood samples of patients with lobar pneumonia identified via X-ray or on cerebrospinal fluid for those with a positive latex agglutination test for Streptococcus pneumoniae. This study was based on the analysis of the serotypes of 1015 Streptococcus pneumoniae cases among children younger than the age of 5: 1006 cases with pneumonia, 6 cases with meningitis, and 3 cases with septicemia. Only 23 culture-positive cases were identified in comparison to 992 lobar pneumonia cases, which were PCR-positive but culture-negative, with a PCR positivity rate of 92%. Serotypes 6B, 6A, 14, and 19F were the most common serotypes identified in this study, with prevalence rates of 16.45%, 13.60%, 12.12%, and 8.18%, respectively. PCV-10, PCV-13, PCV-15, and PCV-20 coverage rates were 45.32%, 61.87%, 64.14%, and 68.47%, respectively. To the best of our knowledge, this is the largest prospective study from the Middle East and one of the largest studies worldwide showing the serotypes of Streptococcus pneumoniae. It reveals the urgency for the introduction of a PCV vaccination in Jordan, utilizing recently developed vaccines with a broader serotype coverage.

Systematic Literature Review of the Epidemiological Characteristics of Pneumococcal Disease Caused by the Additional Serotypes Covered by the 20-Valent Pneumococcal Conjugate Vaccine.

Higher valency pneumococcal conjugate vaccines (PCV15 and PCV20) have been developed to address the disease burden of current non-vaccine serotypes. This review describes the epidemiological characteristics of serotypes beyond PCV13 (serotypes 8, 10A, 11A, 12F, 15B/C, 22F, and 33F; PCV20nonPCV13 serotypes). Peer-reviewed studies published between 1 January 2010 (the year PCV13 became available) and 18 August 2020 were systematically reviewed (PROSPERO number: CRD42021212875). Data describing serotype-specific outcomes on disease proportions, incidence, severity, and antimicrobial non-susceptibility were summarized for individual and aggregate PCV20nonPCV13 serotypes by age group and by type and duration of pediatric PCV immunization program. Of 1168 studies, 127 (11%) were included in the analysis. PCV20nonPCV13 serotypes accounted for 28% of invasive pneumococcal disease (IPD), although the most frequent serotypes differed between children (10A, 15B/C) and adults (8, 12F, 22F). In children, serotype 15B/C tended to be more frequently associated with pneumococcal meningitis and acute otitis media; in adults, serotype 8 was more frequently associated with pneumonia and serotype 12F with meningitis. Serotypes 10A and 15B/C in children and 11A and 15B/C in adults were often associated with severe IPD. Serotype 15B/C was also among the most frequently identified penicillin/macrolide non-susceptible PCV20nonPCV13 serotypes. These results could inform decision making about higher valency PCV choice and use.

#6399 ROLE OF THERAPEUTIC PLASMAPHERESIS IN PAUCI-IMMUNE VASCULITIS – A SINGLE CENTRE EXPERIENCE

Abstract Background and Aims The indication for plasmapheresis (PLF) in pauci-immune vasculitis (PIV) is controversial. This study aimed to characterize the population and renal outcome of patients with PIV undergoing PLF in a hospital in the north of Portugal. Method We conduct a retrospective cohort study of patients followed by a multidisciplinary team, from diagnosis to death or May/22. Two groups were defined: patients undergoing PLF (group A, GA) and not undergoing PLF (group B, GB). Demographic variables, comorbidities, serological subtype, clinical presentation, histological classification and therapeutic were evaluated. Recorded outcomes were death and ESRD (end-stage renal disease) (eGFR,15 ml/min per 1.73 m2, dialysis, or transplantation). Renal survival was estimated using the Kaplan-Meier analysis and differences between curves were evaluated using the log-rank test. Results A total of 72 patients, 26 (36.1%) in group A and 46 (63.9%) in group B were included. In both groups the most frequent serotype was myeloperoxidase ((MPO) (n = 23, GA; n = 38, GB)). In both groups, most patients were male (61.5% in GA and 56.5% in GB), with a mean age at admission of 64 (SD±11.5) and 66.5 years (SD±12.2) in GA and GB, respectively (p = 0.362). Most GA patients had pulmonary and renal involvement on admission (80.7%, n = 21), versus GB (36.9%, n = 17), p&amp;lt;0.05. Mean serum creatinine was superior in GA (6.74 mg/dl, SD ± 2.75) versus GB (3.82 mg/dl, SD±2.95), p&amp;lt;0.05. Twenty patients from GA (76.9%) and 7 from GB (15.2%) required dialysis upon admission, p&amp;lt;0.05. In both groups, almost all patients underwent induction immunosuppression with cyclophosphamide (mean cumulative dose of 4.4 grams (SD ± 2.6) and 5.9 grams (SD ± 2.7), in GA and GB, respectively) and azathioprine in the maintenance phase, with a rapid corticosteroid weaning scheme in both phases. Median follow-up time (months) of GA and GB was 11 (IQR [4.8-37.5]) and 58.5 (IQR [14.5-92]) months. Regarding renal prognosis, 9 of 20 patients in GA and 3 of 7 patients in GB who needed dialysis on admission, partial recover of renal function (p = 1.00). About 37% (n = 17) of patients of GB and 73% (n = 19) of patients of GA reached the composite renal outcome, with a median time of 0 (IQR 0 - 21.8) and 38.5 months (IQR 5.3-92), respectively. GA showed worse renal survival, with a mean of 30.9 months vs. 116.5 months in GB, p = 0.01. Renal survival at 2 years was 68.7% in GB and 24% at GA. Patients in both groups with admission serum creatinine ≥ 5.7 mg/dl had similar renal survival (GA 39.9 and GB 32 months, p = 0.714). Regarding the histological classification, 91.7% and 38.9% in GA and GB belonged to the crescentic class, (p = 0.009). Renal survival in the subgroup of patients with crescentic class was worse in GA (16.6±10.2 vs 83.3±16.1, p = 0.015). The analysis of the Renal Risk Score showed no statistically significant difference between the groups, and between patients with crescentic class in both groups, p = 0.274. Mortality and hospitalization rate due to infection were similar in both groups (p&amp;gt;0.05). Conclusion Patients undergoing PLF had a worse renal outcome, consistent with the higher proportion of patients with severe azotemia and requiring dialysis at admission, in a sample that was mostly ANCA MPO. As described in the literature, the experience of our centre did not demonstrate benefit in the addition of PLF, despite the limitations inherent to an observational, retrospective study and the modest sample size. A better knowledge of etiopathogenesis is essential for the optimization of the therapeutic strategy, together with the promotion of measures that allow timely referral, an early diagnosis and consequent improvement of renal prognosis.

Dynamics of Antibiotic Resistance of Streptococcus pneumoniae in France: A Pediatric Prospective Nasopharyngeal Carriage Study from 2001 to 2022

Epidemiological surveillance of nasopharyngeal pneumococcal carriage is important for monitoring serotype distribution and antibiotic resistance, particularly before and after the implementation of pneumococcal conjugate vaccines (PCVs). With a prospective surveillance study in France, we aimed to analyze the dynamics of pneumococcal carriage, antibiotic susceptibility and serotype distribution in children aged 6 to 24 months who had acute otitis media between 2001 and 2022 with a focus on the late PCV13 period from May 2014 to July 2022. Trends were analyzed with segmented linear regression with autoregressive error. For the 17,136 children enrolled, overall pneumococcal carriage was stable during the study. During the late PCV13 period, the five most frequent serotypes were all non-PCV13 serotypes: 15B/C (14.3%), 23B (11.0%), 11A (9.6%), 15A (7.4%) and 35B (6.5%). During the same period, we observed a rebound of penicillin non-susceptibility (+0.15% per month, 95% confidence interval, +0.08 to 0.22, p &lt; 0.001). Five serotypes accounted for 64.4% of the penicillin non-susceptible strains: 11A (17.5%), 35B (14.9%), 15A (13.9%), 15B/C (9.9%) and 19F (8.2%); non-PCV13/PCV15 accounted for &lt;1%, and non-PCV15/PCV20 accounted for 28%. The next generation PCVs, particularly PCV20, may disrupt nasopharyngeal carriage and contribute to decreasing the rate of antibiotic resistance among pneumococci.

Penicillin-binding protein genotyping of penicillin-nonsusceptible Streptococcus pneumoniae isolates from the nasopharynx of healthy preschool children

Abstract Streptococcus pneumoniae is one of the most frequent bacterial identified causes of community-acquired pneumonia, otitis media and meningitis. It is, as well, a common cause of bacteraemia’s significant morbidity and mortality. Beta-lactam antibiotics (BLAs) are the first line of empirical treatment for pneumococcal infections. The targets of BLAs are penicillin-binding proteins (PBPs), the modifications of which are one of the reasons why pneumococci are non-susceptible to BLAs. In our work, a total of 39 Streptococcus pneumoniae isolates were obtained from 176 healthy children, both vaccinated and non-vaccinated. The isolates were tested for antimicrobial susceptibility, and their penicillin-binding proteins (PBPs) were typed by the restriction fragment length of the polymorphism analysis of their pbp genes. The most frequent serotypes among the penicillin non-susceptible Streptococcus pneumoniae (PNSSP) isolates were 23B, 35B and 19F. Restriction enzyme analyses of pbp1a, pbp2b, and pbp2x genes revealed 5, 3 and 3 different patterns, respectively, and a total of 4 different PBPs profiles of PNSSP isolates belonging to serotypes not included in pneumococcal conjugate vaccines were demonstrated. We conclude that the level of resistance should be monitored constantly to ascertain the effect of current pneumococcal conjugate vaccines, as well as to recognize new circumstances developing in Poland, as well as the possibility of multiple, independent imports of resistant strains from abroad.

Pneumococcal serotypes and antibiotic resistance in healthy carriage children after introduction of PCV13 in Lima, Peru

ObjectiveTo determinate the frequency of Streptococcus pneumoniae nasopharyngeal carriers, serotypes and antimicrobial resistance in healthy children in Lima, Peru, post-PCV13 introduction and to compare the results with a similar study conducted between 2006 and 2008 before PCV7 introduction (pre-PCV7). MethodsA cross-sectional multicenter study was conducted between January 2018 and August 2019 in 1000 healthy children under two years of age. We use standard microbiological methods to determinate S. pneumoniae from nasopharyngeal swab, Kirby Bauer and minimum inhibitory concentration methods to determinate antimicrobial susceptibility and whole genomic sequencing to determinate pneumococcal serotypes. ResultsThe pneumococcal carriage rate was 20.8 % vs. 31.1 % in pre-PCV7 (p < 0.001). The most frequent serotypes were 15C, 19A and 6C (12.4 %, 10.9 % and 10.9 % respectively). The carriage of PCV13 serotypes after PCV13 introduction decreased from 59.1 % (before PCV7 introduction) to 18.7 % (p < 0.001). Penicillin resistance was 75.5 %, TMP/SMX 75.5 % and azithromycin 50.0 %, using disk diffusion. Penicillin resistance rates using MIC breakpoint for meningitis (MIC ≥ 0.12) increased from 60.4 % to 74.5 % (p = 0.001). ConclusionThe introduction of PCV13 in the immunization program in Peru has decreased the pneumococcal nasopharyngeal carriage and the frequency of PCV13 serotypes; however, there has been an increase in non-PCV13 serotypes and antimicrobial resistance.