Colonization, Density, and Antibiotic Resistance of Streptococcus pneumoniae, Haemophilus Influenzae, and Moraxella catarrhalis among PCV13-Vaccinated Infants in the First Six Months of Life in Rochester, New York: A Cohort Study.

BACKGROUND: Streptococcus pneumoniae (Spn), Haemophilus influenzae (Hflu), and Moraxella catarrhalis (Mcat) nasopharyngeal colonization precedes disease pathogenesis and varies among settings and countries. We sought to assess colonization prevalence, density, Spn serotypes, and antibiotic resistance in children in the first 6 months of life in pediatric primary care settings. METHODS: Prospective cohort study in Rochester, NY during 2018-2020. Nasopharyngeal swabs were collected from 101 children at age 1, 2, and 3 weeks, then 1, 2, 4, 6, 9, 12, 15, 18, and 24 months. Spn serotypes were determined by Quellung. Oxacillin resistance for Spn and ß-lactamase production by Hflu and Mcat was tested. All children received PCV13 vaccine according to U.S. recommended schedule. RESULTS: Spn, Hflu, and Mcat colonization was detected in only 5% of infants before age 2 months old. Cumulative prevalence was 34% for Spn, 10% for Hflu, and 53% for Mcat in children ≤6 months of age. Nasopharyngeal bacterial density of Spn, Hflu, and Mcat (x = 2.71 log) in children ≤6 months of age was lower than at 7-24 months of age (x = 3.15 log, p < 0.0001). Predominant serotypes detected ≤6 months of age were 23B (16.7%), 22F (12.9%), 15B/C (11%), and 16F (9.2%). In total, 14.8% of Spn isolates were oxacillin resistant and 66.7% of Hflu isolates were ß-lactamase producing. CONCLUSION: Spn, Hflu, and Mcat nasopharyngeal colonization was uncommon and of low density among children ≤6 months old, especially among children <2 months of age. Non-PCV13 serotypes predominated and a different serotype distribution was observed in ≤6-month olds compared to 7- to 24-month olds.

Changes in Respiratory Pathogens before and after the COVID-19 Pandemic (2018-2021).

Objective: This study is aimed at investigating the pattern of change occurring in respiratory pathogens before and after the outbreak of COVID-19, a type of viral pneumonia for which a pandemic was declared (March 2020). The results were analyzed by gender and age to identify the association between personal hygiene and prevention of infection by respiratory pathogens. Methods: A retrospective analysis was performed on 39,814 sputum, bronchial aspirate, and transtracheal aspirate samples obtained from 15,398 patients visiting a university hospital, located in Chungcheongnam-do, South Korea, between January 2018 and December 2021. From 4,454 patients whose samples were culture positive for bacteria, 6,389 strains were isolated and further cultured. Results: The mean age of the outpatients with respiratory pathogens was 66.2 years, and the comparison of the culture test results by gender showed that 64.9% (2,892/4,454) were male and 35.1% (1,562/4,454) were female. Compared to the pre-COVID-19 pandemic period, the number of outpatients with a request for respiratory microbial cultures after the onset of the pandemic was reduced by 20.7% and the number of outpatients with a positive culture result was reduced by 23.0%. The number of respiratory samples received was reduced by 6.7% after the pandemic, while the sample positive rate was reduced by 18.3%. Among the isolated microbial strains, there was a significant decrease of 43.1% for the Acinetobacter baumannii complex, 60.5% for Streptococcus pneumoniae, 67.2% for Haemophilus influenzae, and 78.1% for Moraxella catarrhalis when compared with pre-COVID-19 levels. The distribution of respiratory microbial strains by age group showed that the highest percentage of isolated strains was in patients in their 70s. Conclusions: The improvements in personal hygiene due to the COVID-19 pandemic exerted a substantial influence on the pattern of change in other common respiratory microorganisms, which highlights the importance of personal hygiene management in the prevention of respiratory infections.

Bacterial Epidemiology and Antimicrobial Resistance Profiles in Children Reported by the ISPED Program in China, 2016 to 2020.

The Infectious Disease Surveillance of Pediatrics (ISPED) program was established in 2015 to monitor and analyze the trends of bacterial epidemiology and antimicrobial resistance (AMR) in children. Clinical bacterial isolates were collected from 11 tertiary care children's hospitals in China in 2016 to 2020. Antimicrobial susceptibility testing was carried out using the Kirby-Bauer method or automated systems, with interpretation according to the Clinical and Laboratory Standards Institute 2019 breakpoints. A total of 288,377 isolates were collected, and the top 10 predominant bacteria were Escherichia coli, Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, Klebsiella pneumoniae, Moraxella catarrhalis, Streptococcus pyogenes, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Acinetobacter baumannii. In 2020, the coronavirus disease 2019 (COVID-19) pandemic year, we observed a significant reduction in the proportion of respiratory tract samples (from 56.9% to 44.0%). A comparable reduction was also seen in the primary bacteria mainly isolated from respiratory tract samples, including S. pneumoniae, H. influenzae, and S. pyogenes. Multidrug-resistant organisms (MDROs) in children were commonly observed and presented higher rates of drug resistance than sensitive strains. The proportions of carbapenem-resistant K. pneumoniae (CRKP), carbapenem-resistant A. baumannii (CRAB), carbapenem-resistant P. aeruginosa (CRPA), and methicillin-resistant S. aureus (MRSA) strains were 19.7%, 46.4%%, 12.8%, and 35.0%, respectively. The proportions of CRKP, CRAB, and CRPA strains all showed decreasing trends between 2015 and 2020. Carbapenem-resistant Enterobacteriaceae (CRE) and CRPA gradually decreased with age, while CRAB showed the opposite trend with age. Both CRE and CRPA pose potential threats to neonates. MDROs show very high levels of AMR and have become an urgent threat to children, suggesting that effective monitoring of AMR and antimicrobial stewardship among children in China are required. IMPORTANCE AMR, especially that involving multidrug-resistant organisms (MDROs), is recognized as a global threat to human health; AMR renders infections increasingly difficult to treat, constituting an enormous economic burden and producing tremendous negative impacts on patient morbidity and mortality rates. There are many surveillance programs in the world to address AMR profiles and MDRO prevalence in humans. However, published studies evaluating the overall AMR rates or MDRO distributions in children are very limited or are of mixed quality. In this study, we showed the bacterial epidemiology and resistance profiles of primary pathogens in Chinese children from 2016 to 2020 for the first time, analyzed MDRO distributions with time and with age, and described MDROs' potential threats to children, especially low-immunity neonates. Our study will be very useful to guide antiinfection therapy in Chinese children, as well as worldwide pediatric patients.

[Current microbiological aspects of community respiratory infection beyond COVID-19]. / Aspectos microbiológicos actuales de la infección respiratoria comunitaria más allá de la COVID-19.

From a microbiological point of view, both empirical and targeted antimicrobial treatment in respiratory infection is based on the sensitivity profile of isolated microorganisms and the possible resistance mechanisms that they may present. The latter may vary in different geographic areas according to prescription profiles and vaccination programs. Beta-lactam antibiotics, fluoroquinolones, and macrolides are the most commonly used antimicrobials during the exacerbations of chronic obstructive pulmonary disease and community-acquired pneumonia. In their prescription, different aspects such as intrinsic activity, bactericidal effect or their ability to prevent the development of resistance must be taken into account. The latter is related to the PK/PD parameters, the mutant prevention concentration and the so-called selection window. More recently, the potential ecological impact has grown in importance, not only on the intestinal microbiota, but also on the respiratory one. Maintaining the state of eubiosis requires the use of antimicrobials with a low profile of action on anaerobic bacteria. With their use, the resilience of the bacterial populations belonging to the microbiota, the state of resistance of colonization and the collateral damage related to the emergence of resistance to the antimicrobials in pathogens causing the infections and in the bacterial populations integrating the microbiota.