Background

Understanding the role of viral co-infection in defining the outcome of paediatric pneumonia will provide novel treatment and prevention strategies, improving patient’s outcome. The objective of this study was to determine the prevalence of viral infection in children with pneumonia

Methods

128 Nasopharyngeal swabs of children with clinically proven pneumonia collected from a tertiary care hospital in a duration of 1 year were tested. Multiplex real-time PCR assay- FTIyo Respiratory pathogens 33 test kit (Fast-Track Diagnosis, Luxembourg) was used for analysis.

Results

105/128(82%) of children included in the study tested positive for at least one pathogen: bacterial or viral. Viral infection was detected in 55/128(42%) of samples. Pure viral infection was present in 12%(7/55) of cases. Single viral co-infection accounted for 67%(37/55) of cases. Co-infection with duel virus was detected in 10 patients(18%) and triple infection in 1.8% (1/55).

The most common viruses identified were Adenovirus(47%), Bocavirus(32%), Rhinovirus (21%), Human Parainfluenza Viruses HPIV3(12%), HPIV4(3.63%) and Respiratory syncytial viruses A and B(3.63%) respectively

Conclusions

The study highlights the importance of evaluating viral co-infection in the context of pneumonia in children. It is an ideal approach for better understanding of the carriage with multiple viral agents and its relationship with the bacterial pathogen.

Background

Streptococcus pneumoniae is a human opportunistic pathogen responsible for morbidity and mortality worldwide. Pneumococcal surface protein, Choline-binding protein A (CbpA) plays a key biological role in nasopharyngeal colonization and modulating the immune response to pneumococci. We have analyzed the genetic diversity of cbpA in invasive isolates.

Methods

264 invasive S.pneumoniae isolates collected from 2010-2018, were sequenced on Illumina Platform. The CRL in-house bioinformatics pipeline was used to extract gene sequences, alignment and phylogeny analysis. Allelic variations of CbpA gene was analyzed by comparing the identity with a well-defined virulent strain of S. pneumoniae TIGR4.

Results

Gene cbpA was identified in 261(99%) of the 264 genomes. The sequences were highly polymorphic at both nucleotide and amino acid levels. Similarity of cbpA gene ranged from 65 – 98%, while 80- 99% homology was observed at amino acid level. Amino acid residues with similar physicochemical properties aligned allowing the identification of broadly conserved CbpA domains.

Conclusions

Due to high polymorphism at the cbpA locus, analysis of this loci from different isolates highlights how sequence diversity correlates with structural variation. The conserved epitope regions of the CbpA protein fragments can be exploited to develop more efficacious serotype-independent vaccines.

Background

Serotype 1 Streptococcus pneumoniae is a common cause of IPD in India. The present study describes the phylogeny, clonality and antimicrobial susceptibility pattern of the isolates collected in the pre-PCV era in India.

Methods

21 invasive serotype 1 pneumococcal isolates collected across India during 2009-2016, were sequenced on Illumina platform. Phylogenetic tree was built with REALPHY 1.12. Abricate software with VFDB was used to analyse virulence genes and CDC Pneumococcal specific pipeline was used for antimicrobial resistance gene identification.

Results

Population structure analysis of the strains showed that 20 of them belong to sequence cluster GPSC2 and one to GPSC31. MLST resolved the isolates to 8 known STs and four clonal complexes CC217, CC5191, CC5316 and CC303. CC217 (n=16) was the most prevalent clonal complex, followed by CC5191 (n= 3). 90% (n=19) of the isolates harboured the virulence factors, lytA, nanA, hasC, pspA, srtG1, srtG2. Phenotypic and genomic analysis demonstrated sensitivity to penicillin, erythromycin and vancomycin of all 21 isolates; six isolates were resistant to cotrimoxazole and one to tetracycline.

Conclusions

With the introduction of pneumococcal vaccine in the national immunization programme in 2017, this study provides baseline data for future analyses.

Background

Pneumococcal Conjugate Vaccine (PCV) use has resulted in decrease of vaccine serotypes (VTs) and emergence of non-vaccine types (NVTs). We applied whole genome sequence (WGS) to predict serotype, sequence type (ST) and antibiotic resistance of NVT invasive pneumococcal isolates collected during the pre-vaccine era from Indian population.

Methods

96 NVT invasive isolates (2009-2017) collected across the country were sequenced on Illumina platform. Bioinformatic pipelines SeroBA and CDC pneumococcal pipeline for AMR calls were used for data analysis.

Results

Serotypes 15B (n=11), 24 (n=9) were dominant NVT types followed by 8 (n=8) and 34,10A,11A,16F (n=5). MLST resolved strains into 67 known STs. ST13727 (n=6) and ST2234 (n=5) were most common. Strains clustered in 45 clonal complexes and 16 singletons. The dominant clonal complex CC230 (n=12) was from serotypes 15B,15C,24,10A and 11A. 78(81%) of isolates were multidrug-resistant. Resistance genes for tetracycline (n=44), cotrimoxazole (n=41), erythromycin (n=34), penicillin (n=13) and chloramphenicol (n=2) were identified.

Conclusions

With the introduction of PCV in 2018 in national immunization program our data provides information for post-vaccination assessments. With higher valency vaccines coming to market by Indian manufacturers, knowledge of PCV13 NVT disease is important to identify serotypes to expand vaccine coverage in India.

Background

Streptococcus pneumoniae is a leading cause of meningitis. Intense inflammatory response observed in meningitis is partially attributed to zinc metalloprotease encoded by zmpB in pneumococcal strains. We aimed to study allelic variations of zmpB among isolates obtained from Meningitis patients

Methods

36 cerebrospinal fluid (CSF) isolates collected across the country from 2009-2016 were sequenced on Illumina platform. The CRL in-house bioinformatics pipeline was used to extract gene sequences, alignment and phylogeny analysis. SeroBA was used to determine serotype. Allelic variations of zmpB gene was analyzed by comparing the identity with the virulent strain S. pneumoniae TIGR4.

Results

36 pneumococcal isolates belong to 24 serotypes with 19F(n=5) as dominant type. Non-PCV13 vaccine serotypes constituted 50% of the isolates(n=18). The isolates were assigned to 28 sequence clusters, among them GPSC10(n=4) & GPSC2(n=3) were predominant.32 of 36 isolates showed 21 to 88% of sequence variation, while remaining 4 isolates showed sequence similarity of 98% with the TIGR4. Allelic variations did not affect the protein coding region analysis and conserved domains of ZmpB protein was identified in all isolates.

Conclusions

The findings provide insight on the allelic variations of zmpB, indicating there is a high degree of polymorphism in the sequence of zmpB in pneumococci causing meningitis.

Background

Serotype 2 was a major cause of pneumococcal pneumonia about 100 years ago and then disappeared. Recently, serotype 2 re-emerged in many countries, including Bangladesh and associated with meningitis. This study aims to understand genomic and epidemiological characteristics of newly emerged serotype 2 strains.

Methods

Whole-genome sequencing was performed on 146 isolates (invasive= 125, carriage= 8 and other= 5, unknown= 8) collected between 1989 and 2017. Data were analyzed for comparative genomics, antimicrobial resistance and molecular typing.

Results

Isolates were from 16 countries, mostly in Asia (n=93), Africa (n=23) and Oceania (n=26). Bangladesh (n=66) and Papua New Guinea (n=26) contributed 63% of the isolates. Among the known clinical conditions, 80% (91/113) were from meningitis. All isolates belonged to GPSC96 lineage and descended from two predominant sequence types: ST74 found in Asia and Africa, and ST1504 found in Papua New Guinea and Israel. Almost all isolates were sensitive to all antibiotics. No significant genetic differences were detected between invasive and carriage isolates.

Conclusions

Our findings don’t explain why the recent increase in serotype 2 occurred but exclude an outbreak or emergence of an antimicrobial-resistant strain as the cause. These isolates have unusually high propensity to be invasive, mostly causing meningitis.