Clinical and microbiological implications of invasive pneumococcal disease in hospitalized patients (1998-2013)

Exploring the efficacy of tryptone-stabilized silver nanoparticles against respiratory tract infection-causing bacteria: a study on planktonic and biofilm forms

Respiratory tract infections (RTIs) are a common cause of mortality and morbidity in the human population. The overuse of antibiotics to overcome such infections has led to antibiotic resistance. The emergence of multidrug resistant bacteria is necessitating the development of novel therapeutic techniques in order to avoid a major global clinical threat. Our study aims to investigate the potential of tryptone stabilised silver nanoparticles (Ts-AgNPs) on planktonic and biofilms produced byKlebsiella pneumoniae(K. pneumoniae)and Pseudomonas aeruginosa(P. aeruginosa). The MIC50of Ts-AgNPs was found to be as low as 1.7 μg ml-1and 2.7 μg ml-1forK. pneumoniae and P.aeruginosarespectively. Ts-AgNPs ability to alter redox environment by producing intracellular ROS, time-kill curves showing substantial decrease in the bacterial growth and significantly reduced colony forming units further validate its antimicrobial effect. The biofilm inhibition and eradication ability of Ts-AgNPs was found to be as high as 93% and 97% in both the tested organisms. A significant decrease in the eDNA and EPS quantity in Ts-AgNPs treated cells proved its ability to successfully distort the matrix and matured biofilms. Interestingly Ts-AgNPs also attenuated QS-induced virulence factors production. This study paves way to develop Ts-AgNPs as novel antibiotics against RTIs causing bacterial biofilms.

Impact after 10-year use of pneumococcal conjugate vaccine in the Brazilian national immunization program: an updated systematic literature review from 2015 to 2020

In 2010, a 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) was introduced in the Brazilian national immunization program; the 3 + 1 dose schedule was replaced by a 2 + 1 dose schedule in 2016. This systematic review presents the latest published evidence (2015–2020) on the impact after 10-year use of PHiD-CV in Brazil from a total of 29 publications. Overall, the PHiD-CV program had a positive impact on the morbidity and mortality associated with invasive pneumococcal disease (IPD), pneumonia and acute otitis media (AOM) in children <5 years-old. A reduction in the vaccine-type invasive disease was observed in all-ages; suggesting indirect protection unvaccinated older children and adults. The occurrence of non-vaccine type disease was evidenced in some studies. Higher vaccination coverage is required at national and state level for sustained population impact. Given the change in the vaccination schedule and the dynamics of pneumococcal disease epidemiology, continuous surveillance is warranted.

GSK Study identifier: HO-18-19438

Distribution of PCV13 and PPSV23 Streptococcus pneumoniae serotypes in Argentinean adults with invasive disease, 2013-2017

Streptococcus pneumoniae is a major cause of severe invasive disease associated with high mortality and morbidity worldwide. To identify the serotypes most commonly associated with infection in adults in Argentina, 791 pneumococcal isolates from 56 hospitals belonging to 16 provinces and Buenos Aires city were serotyped. The isolates were submitted as part of a National Surveillance Program for invasive pneumococcal disease in adults, which started in 2013. Serotypes 3, 8, 12F, 7F and 1 were the most prevalent among adult patients. During the study period there was no significant difference in serotype distribution between the age groups studied (18-64 and ≥65 years old), except for serotype 1, 3 and 23A. Most prevalent serotypes in pneumonia were serotype 7F, 1, 12F, 8, and 3. When the clinical diagnosis was meningitis, serotype 3 and 12F were the most prevalent, whereas when the diagnosis was sepsis/bacteremia the most prevalent was serotype 8. In this work, for the 18-64-year-old group, PPSV23 and PCV13 serotypes accounted for 74.56% and 44.54% respectively of the cases in the studied period. On the other hand, for the ≥65-year-old group, these serotypes represented 72.30% and 41.42% respectively. The aim of this work was to establish the knowledge bases of the serotypes that cause invasive pneumococcal diseases in the adult population in Argentina and to be able to detect changes in their distribution over time in order to explore the potential serotype coverage of the vaccines in current use.

Epidemiology of invasive and non-invasive pneumococcal infections in hospitalised adult patients in a Lebanese medical centre, 2006-2015

This is a retrospective medical file review of adult inpatients with Streptococcus pneumoniae infections admitted to a Lebanese hospital between 2006 and 2015. We revisited the clinical scenarios of these infections in view of increasing antibiotic resistance in Lebanon. One hundred and three patients were included; 92% were eligible for pneumococcal vaccination, yet none were vaccinated. Non-invasive pneumococcal disease (non-IPD) represented 64% of these infections. Superinfections caused by antibiotic-resistant bacteria were documented in 17.5% of the patients, with the predominance of ventilator-associated pneumonia (12.6%). Kidney disease and septic shock were positive predictors for mortality [adjusted odds ratio (OR) = 14.96, 95% confidence interval (CI) 2.34-95.45, P = 0.004; OR = 5.09, 95% CI 1.33-19.51, P = 0.02, respectively]. Herein, the differences in clinical success, S. pneumoniae infection-related death, and total mortality were not statistically significant between invasive pneumococcal disease (IPD) and non-IPD subgroups (59.5% vs. 77.3%, P = 0.056; 21.6% vs. 9.1%, P = 0.08; and 35.1% vs. 22.7%, P = 0.174; respectively). Upon comparing antibiotic susceptibility of S. pneumoniae during the first two years of the study (2006-2007) (n = 32 isolates) and the last two (2014-2015) (n = 14 isolates), there was an increasing non-susceptibility to penicillin (34.4%-50.0%, P = 0.25), and a decreasing susceptibility to erythromycin and clindamycin (81.3%-78.6%, P = 0.67 and 90.6%-85.7%, P = 0.65; respectively).