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Background: Acute pneumonia remains a leading cause of death among children below 5 years of age in the Democratic Republic of the Congo (DR Congo), despite introduction of the 13-valent pneumococcal conjugate vaccine (PCV13) in 2013. Potential pathogens in the nasopharynx of hospitalised children with pneumonia have not been studied previously in DR Congo. Here we compare clinical characteristics, risk factors and nasopharyngeal occurrence of bacteria and viruses between children with severe and non-severe pneumonia., Methods: Between June 2015 and June 2017, 116 children aged from 2 to 59 months hospitalised due to radiologically confirmed pneumonia at Panzi referral university hospital, Bukavu, Eastern DR Congo were included in the study and sampled from nasopharynx. A multiplex real-time PCR assay for detection of 15 different viruses and 5 bacterial species was performed and another multiplex PCR assay was used for pneumococcal serotype/serogroup determination., Results: During the study period 85 (73%) of the children with radiologically confirmed pneumonia met the WHO classification criteria of severe pneumonia and 31 (27%) had non-severe pneumonia. The fatality rate was 9.5%. Almost all (87%) children were treated with antibiotics before they were hospitalised, in most cases with amoxicillin (58%) or trimethoprim-sulfamethoxazole (20%). The frequency of potential pathogens in the nasopharynx of the children was high, and any viral or bacterial nucleic acids present at high levels, irrespective of species or type, were significantly associated with severe pneumonia as compared with non-severe cases (52% versus 29%, p = 0.032). White blood cell count > 20,000/μL and C-Reactive Protein > 75 mg/dL were associated with severe pneumonia at admission. Fatal outcome was in the multivariable analysis associated with having a congenital disease as an underlying condition. One or more pneumococcal serotypes/serogroups could be identified in 61 patients, and out of all identified serotypes 31/83 (37%) were non-PCV13 serotypes., Conclusions: The occurrence of any bacteria or any viruses at high levels was associated with severe pneumonia at admission. Children with congenital disorders might need a higher attention when having symptoms of acute respiratory infection, as developed pneumonia could lead to fatal outcome., (© 2021. The Author(s).)

Background: Pneumococcal conjugate vaccines have been introduced in the infant immunisation programmes in many countries to reduce the rate of fatal pneumococcal infections. In the Democratic Republic of the Congo (DR Congo) a 13-valent vaccine (PCV13) was introduced in 2013. Data on the burden of circulating pneumococci among children after this introduction are lacking. In this study, we aimed to determine the risk factors related to pneumococcal carriage in healthy Congolese children after the vaccine introduction and to assess the antibiotic resistance rates and serotype distribution among the isolated pneumococci., Methods: In 2014 and 2015, 794 healthy children aged one to 60 months attending health centres in the eastern part of DR Congo for immunisation or growth monitoring were included in the study. Data on socio-demographic and medical factors were collected by interviews with the children's caregivers. Nasopharyngeal swabs were obtained from all the children for bacterial culture, and isolated pneumococci were further tested for antimicrobial resistance using disc diffusion tests and, when indicated, minimal inhibitory concentration (MIC) determination, and for serotype/serogroup by molecular testing., Results: The pneumococcal detection rate was 21%, being higher among children who had not received PCV13 vaccination, lived in rural areas, had an enclosed kitchen, were malnourished or presented with fever (p value < 0.05). The predominant serotypes were 19F, 11, 6A/B/C/D and 10A. More than 50% of the pneumococcal isolates belonged to a serotype/serogroup not included in PCV13. Eighty per cent of the isolates were not susceptible to benzylpenicillin and non-susceptibility to ampicillin and ceftriaxone was also high (42 and 37% respectively). Almost all the isolates (94%) were resistant to trimethoprim-sulphamethoxazole, while 43% of the strains were resistant to ≥3 antibiotics., Conclusions: Our study shows alarmingly high levels of reduced susceptibility to commonly used antibiotics in pneumococci carried by healthy Congolese children. This highlights the importance of local antibiotic resistance surveillance and indicates the needs for the more appropriate use of antibiotics in the area. The results further indicate that improved living conditions are needed to reduce the pneumococcal burden, in addition to PCV13 vaccination.

Background: Enterotoxigenic Escherichia coli (ETEC) is a major cause of diarrhea in children and travelers to endemic areas. Secretion of the heat labile AB 5 toxin (LT) is induced by alkaline conditions. In this study, we determined the surface proteome of ETEC exposed to alkaline conditions (pH 9) as compared to neutral conditions (pH 7) using a LPI Hexalane FlowCell combined with quantitative proteomics. Relative quantitation with isobaric labeling (TMT) was used to compare peptide abundance and their corresponding proteins in multiple samples at MS/MS level. For protein identification and quantification samples were analyzed using either a 1D-LCMS or a 2D-LCMS approach., Results: Strong up-regulation of the ATP synthase operon encoding F1Fo ATP synthase and down-regulation of proton pumping proteins NuoF, NuoG, Ndh and WrbA were detected among proteins involved in regulating the proton and electron transport under alkaline conditions. Reduced expression of proteins involved in osmotic stress was found at alkaline conditions while the Sec-dependent transport over the inner membrane and outer membrane protein proteins such as OmpA and the β-Barrel Assembly Machinery (BAM) complex were up-regulated., Conclusions: ETEC exposed to alkaline environments express a specific proteome profile characterized by up-regulation of membrane proteins and secretion of LT toxin. Alkaline microenvironments have been reported close to the intestinal epithelium and the alkaline proteome may hence represent a better view of ETEC during infection.